`let` and `subject` declarations are not intended to be called
in a `before(:context)` hook, as they exist to define state that
is reset between each example, while `before(:context)` exists to
define state that is shared across examples in an example group.enter code here

and here is the code where it's breaking

let(:model) { described_class } # the class that includes the concern

before(:all) do
@queue = FactoryGirl.create(model.to_s.underscore.to_sym)
end